Photocopy meter

ABSTRACT

A system to meter strip advances in photocopying apparatus is described in which the strip and a metering roll travelling together precisely are stopped intermittently by cogs fixed to the roll coming to abut a stop element at intervals proportioned to predetermined advances of the strip.

United States Patent Inventor Stanley F. Staples 4110 Wheeler Ave.,Alexandria, Va. 22304 Appl. No. 830,303 Filed June 4, 1969 Patented Dec.14, 1971 PHOTOCOPY METER 3 Claims, 1 Drawing Fig.

US. Cl 355/64, 95/31 EL, 226/136, 226/141 lnt.Cl G03b l/l4, G03b l/32,G03b 1/40 Field of Search 355/64; 95/31 FS,31 AC, 31 EL; 226/24, 27,137,136, 139, 141

References Cited UNITED STATES PATENTS 2,632,369 3/1953 Estes 95/31FSL2,652,209 9/1953 Hodges. 242/71 2,748,861 6/1956 Stoeser..... 226/136X2,927,790 3/1960 Tyleretal 95/31 51.x

Primary Examiner-.loseph F. Peters, Jr. Assistant Examiner-Russell E.Adams, Jr. Attorney-J. Howard Flint ABSTRACT: A system to meter stripadvances in photocopying apparatus is described in which the strip and ametering roll travelling together precisely are stopped intermittentlyby cogs fixed to the roll coming to abut a stop element at intervalsproportioned to predetermined advances of the strip.

PATENTED DEC] 4 Ian INVENTUR STANLEY F. STAPLES PHOTOCOPY METER Thisinvention applies to photocopying apparatus and serves to meter and stopa moving sensitive strip at a given position with great accuracy. Thestrip stops momentarily for some particular treatment, then continues.This invention aligns successive advances at the treatment station, forexample a strip of paper or film at a copying station precisely.

Need for exact positioning is readily apparent. Toillustrate, if an inchspace is intended to be left between exposures then an )6 inch variancein stopping the film can mean over 12 percent error. This might well becumulative. The problem is old, but suggested cures have not beensatisfactory; overrun and underrun remain serious faults.

Difficulties are compounded when the apparatus must be adaptable to stopthe strip at different distances. When different predetermined lengthsare desired, the stopping mechanism must be versatile. In some cases thechanges of advance may be in given multiples, as for example when agiven set of advances is to be in multiples of a half inch, longer orshorter than previously. Or, the change may be extended to some multipleof other units, as change from half inch increments to some multiple ofseven-eights inch. The stopping must still be accurate.

Objects of this invention are to meet various sources of error in anoperating machine. Such are play and tolerances in moving parts, timedelays and many sources of sluggish action. Another object is tomaintain high and continued precision in stopping advances of a filmstrip at predetermined intervals. Other objects are to provideversatility and ease of adjustment in apparatus to change from onedistance of advance to another and to change or adjust to meter strip ofone quality or another. (It is clear that this apparatus does not dependon sprocketed film). Other objects and advantages of this invention willappear from the following detailed description of the preferredembodiment of this invention as shown in the attached drawing.

Novel features of this invention are set out in the accom panyingclaims.

The drawing shows a schematic arrangement of the combination of partsforming the preferred embodiment of this invention. v

The drawing shows a strip 1 drawn by power of motor 2 from a supply roll3 to accumulate on a takeup roll 4. Strip 1 travels over variouspositioningrolls. Such are illustrated as rolls 5 and 6 at the beginningof a flat path of travel of strip 1 and roll 7 nearer terminal roll 4.As means to meter advances of strip 1 and also to control stopping ofthe strip, roll 8 is placed at the end of the flat path of travel shown.Roll 7 is positioned to wrap strip 1 around a substantial at leastsemicircular arc of roll 8.

Motor 2 drives takeup roll 4, as illustrated by belt 9. Drive ofmetering roll 8 may include, to a greater or less extent, power throughadjustable belt 10. However, metering roll 8 may be rotated sufficientlyby the grip and pull of strip 1 being drawn over its substantial contactwith roll 8. This is in part a matter of choice and in part a matter ofthe nature of strip 1. The objective is such drive that the lineartravel of strip 1 and of the periphery of roll 8 in contact therewithare precisely the same in any given situation.

Strip 1 is to stop intermittently at a predetermined position 11. Atthis position an operation of one sort or another is performed on thestopped strip 1 by suitable known means depending on the purpose, forexample exposure by photographic means 33. After this operation atstation 11, strip 1 moves forward again to bring up the next portion tostopping position 11. This advances the first portion by a distancedesignated as X in the drawing, to some position 12. The extent of thisadvance X, or the location of position 12, may differ from one situationto another, so variation of position 12 is indicated by opposed arrows.In any event, a point on strip 1 first occupying position 11 will nextoccupy a particular position 12 exactly.

ln this description and claims the extent that strip 1 moves forwardeach interval is termed the advance. The portion of the advance occupiedby a photographic exposure is termed a frame. Each frame normally isbounded by a margin at least at each end within the advance. If theadvance is increased or decreased in given case, this change is termedan increment.

Certain features of the'combination of parts in this invention fix theprecision of stopping the advances of strip 1.

Peripheral cogs 27, as in wheel 26-27, are attached rigidly to meteringroll 8. On movement to a predetermined extent, an appropriate cog 27 isbrought to abut a rigid stop 28 at a fixed point. This necessarily haltsthe travel of roll 8 and of strip 1 exactly at the target position, forroll 8 and strip 1 in contact therewith move and stop togetherprecisely. Subsequently, the cog is released and advance of strip 1 isresumed.

Travel of strip 1, to control this operation of stopping the advance,acts not only through cogs 27 but also through power means to bring therigid stop 28 into proper position ahead of a cog 27.

The drawing shows rigid stop 28 as a pawl having arm 14 pivoted at afixed point and rotatable into and out of engagement position with a cog27. The pawl end opposite to face 28 is continually under pull of spring25 directed to move the face 28 down in front of a cog 27. The same pawlend is subjected to opposing power by connection to electromagnet 24. Inclosed circuit the pull of the element 24 is sufficient to overcomespring 25 and raise and latch pawl face 28 from engagement with cog 27.In open circuit, electromagnet 24 is deenergized and releases the pawlto move into position under power of spring 25. The continual pull ofelement 25 aids in easing the release of pawl face 28 when power ofelectromagnet 24 is applied after a cog has been stopped. A jerky orkick type of release is less desirable.

A combined counter and variable switch 13 is operated by metering roll 8to cause quick power control of electromagnet 24 in circuit 23 and, ifdesired, of motor 2. Circuit 23 and the circuit to motor 2 are part of aprincipal circuit 18.

Roll 8 drives counterswitch 13"by belt 21. This element 13 comprises apair of rotatable hands 19 and 22. Hand 22 is settable to indicate apredetermined amount of travel or ad vance of strip 1 with roll 8 whilehand 19 is moved along part 15 of circuit 18 between terminals 16-16 and17. Hand 19 comes to open this circuit at terminal 16'. This opens thecircuit of electromagnetic pawl latch 24, and, as shown in the drawing,of motor 2 also. Normally both hands 19 and 22 are set at the samepoint, from which hand 19 is moved over incremental points 20. Hand 22is not a part of the circuit. When hand 19 opens the circuit at terminal16, the circuit may be left open until 19 is returned later; or, hand 19may be springbiased to return at once to itssetting, as indicated byopposed arrows in the drawing. In the latter case the circuit continuesopen automatically through a holding circuit indicated by numeral 32 incircuit 18 until manually or automatically closed. Both counterswitch 13and holding circuit 32 are well-known types of themselves and need nofurther description.

To revert to cogs 27, corresponding faces are spaced apart a distancethat is a desired discrete proportion of the strip advance. This bears asimple fractional relation to the circumference of roll 8, or the numberof cogs on a given roll. For example, if there are 6 cogs 27 and thecircumference of roll 8 is 12 inches, then each cog is spaced tocorrespond to 2 inches of travel of that circumference and also ofstrip 1. 1f the advance X of strip 1 each period is 4 inches thenrotation of two cogs 27 and their spaces 26 past a given point fixeseach 4-inch advance of strip 1. This is a precise position since eachcog face to be engaged comes to abut pawl face 28 at a precisely fixedpoint.

An important consideration in determining the relationship of pawl face28 and cog 27 is to provide that the face 28 makes contact at a pointwhere the cog face is tangent to the circle of rotation of the pawl.That is, a radius from the fixed center of swing of pawl face 28 throughthe contact of the face meets the cog face 27 at right angles asindicated by dotted line 34. lnthis arrangement the pawl lifts upwithout binding when the electromagnet 24 acts and on the other hand thepawl is not loose when holding a cog. This is important especially whenthe cogs are operated by motor 2 and slip clutch 31 so that power isexerted between cog 27 and pawl face 28. A binding against cog 27tending to kick the cog would tend to slide strip 1 relatively to roll 8rather than maintain desired fixed contact.

The drawing shows each of the equal spaces between adjacent cogssomewhat wider than the end of pawl 14. This permits the pawl to enterthe space and be in position wherever it may in front of the appropriatecog and permits the oncoming cog to move more or less until stopped byabutting pawl face 28. This freedom of movement absorbs whatever erraticaction there may be in the mechanisms; yet stopping the travel of strip1 occurs exactly at the fixed meeting point of cog and pawl. The drawingshows the top surface of the cogs as flat, to permit limited travel ofcog 27 and strip 1 even if the pawl happens to descend upon the top ofthe cog ahead of the selected one. In many cog and pawl arrangements thecogs are so close together or otherwise made that a pawl may engage onecog or another without certainty. In the present invention the pawlcomes to abut only the intended cog as spaces 26 are relatively about aswide or wider than cogs 27 themselves.

It is clear that the number and strip coverage of cogs 27 may vary,depending on circumference of roll 8 and the desired advance X ofstrip 1. Also by changing the cog wheel 26-27 to another wheel having adifferent number of cogs, a different range of cog coverage of striptravel may be substituted. In any case, increments of strip advancecorrespond to a given cog spacing. If instead of the six cogs 27 shownin the drawing there were 24 cogs, for example, with the 12-inchcircumference of roll 8, then each increment would be one-half inch.Each space 26 or each increment of strip 1 advance is a discreteproportion of the advance.

Selection of a desired number of increments or of strip advance in agiven case is by setting indicator hand 22, if desired, and switch hand19, on a chosen marker 20 for hand 19 to be moved the remaining distanceto terminal 16. The spacing of markers 20 is proportioned to thedistance between cogs 27, as by arrangement of the switch drive fromroll 8 such as shown in the drawing. Thus variable switch 19 isoperative at different positions connected to release pawl 14 atcorresponding different positions of advance of roll 8 and a cog 27 intopawl abutment position. Thus advance of strip 1 may be increased ordecreased by the number of increments or cogs rotated before pawl 14 isdropped in front of a predetermined cog 27.

To afford delicate control of movement of strip 1, this apparatuspreferably includes variable brakes and clutches. The drawing shows avariable clutch 29 on motor 2 to regulate belt pull. A slip-clutch 31may apply to roll 8 if desired to minimize the shock of sudden stoppingof cog wheel 26-27. A slight tension preferably is maintained by takeuproll 4 so as to keep strip 1 suitably taut at all times. Similarlysupply roll 3 is served by adjustable brake 30 to aid in maintainingstrip 1 suitably taut.

Those skilled in the art will now be able to provide equivalent elementsto those shown in the drawing. For example instead of electric power andcomponents, fluidic power may be equivalent for many uses of thisinvention. Also other changes and equivalent operations may be madewithin the scope of the appended claims. In accordance with the PatentStatutes, a preferred embodiment and presently best mode of operationhave now been set forth in this description of this invention.

What is claimed is:

1. ln photocopying apparatus having means to advance a sensitized stripand means to maintain the strip under tension at a takeup roll, means tostop the strip advance intermittently and means to expose the stoppedstrip, the combination of stopping means comprising a metering rollpositioned to have its peripheral face in extensive, at leastsemicircular, adjustable contact with the advancing strtirp, means toadjust said strip contact, separate means to drive e roll connected tothe re l and adjustable in conjunction with adjustment of the advancingstrip to obtain linear advance of the roll peripheral face and of thestrip precisely the same, a series of cogs fixed to the side of themetering roll, a pawl mounted to be brought into position to abut a cogand thus stop the roll, the cogs having faces adapted to abut the pawlat fractional circumferential distances apart in discrete proportion tothe strip advance, means to latch the pawl out of cog abutment, means tomove the pawl into said abutment position, and control means connectedto the pawl latch means and to the metering roll and operative by theroll itself in its advance to release the pawl latch means atpredetermined advance of the roll and enable the aforesaid pawl-movingmeans to move the pawl into a corresponding roll-stopping abutmentposition, thereby stopping the roll and the strip advance.

2. Photocopying apparatus as claimed in claim I wherein the said meansto move the pawl into cog abutment position is applied continually andthe said control means comprises means to latch the pawl out of saidabutment position and comprises electric circuit means includingvariable switch means connected for operation by the roll itself in itsadvance to release said pawl latch means by predetermined advance of theroll to bring a cog and pawl into rollstopping abutment position.

3. Photocopying apparatus as claimed in claim 1 wherein the said meansto latch the pawl out of cog abutment is electromagnetic and the saidcontrol means comprises an electric circuit including both the latchmeans and a switch means operative by the roll itself in its advance torelease the latch means at predetermined advance of the roll.

i i i i i

1. In photocopying apparatus having means to advance a sensitized stripand means to maintain the strip under tension at a takeup roll, means tostop the strip advance intermittently and means to expose the stoppedstrip, the combination of stopping means comprising a metering rollpositioned to have its peripheral face in extensive, at leastsemicircular, adjustable contact with the advancing strip, means toadjust said strip contact, separate means to drive the roll connected tothe roll and adjustable in conjunction with adjustment of the advancingstrip to obtain linear advance of the roll peripheral face and of thestrip precisely the same, a series of cogs fixed to the side of themetering roll, a pawl mounted to be brought into position to abut a cogand thus stop the roll, the cogs having faces adapted to abut the pawlat fractional circumferential distances apart in discrete proportion tothe strip advance, means to latch the pawl out of cog abutment, means tomove the pawl into said abutment position, and control means connectedto the pawl latch means and to the metering roll and operative by theroll itself in its advance to release the pawl latch means atpredetermined advance of the roll and enable the aforesaid pawl-movingmeans to move the pawl into a corresponding roll-stopping abutmentposition, thereby stopping the roll and the strip advance. 2.Photocopying apparatus as claimed in claim 1 wherein the said means tomove the pawl into cog abutment position is applied continually and thesaid control means comprises means to latch the pawl out of saidabutment position and comprises electric circuit means includingvariable switch means connected for operation by the roll itself in itsadvance to release said pawl latch means by predetermined advance of theroll to bring a cog and pawl into roll-stopping abutment position. 3.Photocopying apparatus as claimed in claim 1 wherein the said means tolatch the pawl out of cog abutment is electromagnetic and the saidcontrol means comprises an electric circuit including both the latchmeans and a switch means operative by the roll itself in its advance torelease the latch means at predetermined advance of the roll.